diff --git a/.idea/misc.xml b/.idea/misc.xml
index 0ebe0b863..89dc5b1d5 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -8,4 +8,4 @@
   <component name="SuppressKotlinCodeStyleNotification">
     <option name="disableForAll" value="true" />
   </component>
-</project>
\ No newline at end of file
+</project>
diff --git a/build.gradle.kts b/build.gradle.kts
index 75049c436..3ecfd529b 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -46,7 +46,7 @@ dependencies {
      * https://github.com/asciidoctor/asciidoctorj-pdf/issues/25
      */
     implementation("org.snakeyaml:snakeyaml-engine:2.7")
-    implementation("org.asciidoctor:asciidoctorj:2.5.13") // WARNING: when upgrading asciidoctorj, see comment above about snakeyaml!
+    implementation("org.asciidoctor:asciidoctorj:3.0.0") // WARNING: when upgrading asciidoctorj, see comment above about snakeyaml!
     implementation("commons-io:commons-io:2.16.1")
     implementation("io.github.markdown-asciidoc:markdown-to-asciidoc:2.0.1") {
         // Exclude the Kotlin dependency, as this plugin uses only the Java version of the converter.
diff --git a/src/main/java/org/asciidoc/intellij/AsciiDocWrapper.java b/src/main/java/org/asciidoc/intellij/AsciiDocWrapper.java
index 9b82f6640..420a59cc4 100644
--- a/src/main/java/org/asciidoc/intellij/AsciiDocWrapper.java
+++ b/src/main/java/org/asciidoc/intellij/AsciiDocWrapper.java
@@ -1331,7 +1331,7 @@ private static void handleAntoraYamlException(YAMLException ex, @Nullable String
 
   public Options getExportOptions(Options options, FileType fileType) {
     if (fileType == FileType.HTML || fileType == FileType.BROWSER || fileType == FileType.DOCX) {
-      options.setOption(Options.HEADER_FOOTER, true);
+      options.setOption(Options.STANDALONE, true);
     }
     return options;
   }
@@ -1411,10 +1411,13 @@ private Options getDefaultOptions(FileType fileType, VirtualFile
 
     settings.getAsciiDocPreviewSettings().getAttributes().forEach(attrs::setAttribute);
 
-    OptionsBuilder opts = Options.builder().safe(settings.getSafe(project)).backend(fileType.backend).headerFooter(false)
+    OptionsBuilder opts = Options.builder().safe(settings.getSafe(project)).backend(fileType.backend).standalone(false)
       .attributes(attrs)
-      .option("sourcemap", "true")
-      .baseDir(fileBaseDir);
+      .option("sourcemap", "true");
+
+    if (fileBaseDir != null && fileBaseDir.exists()) {
+      opts = opts.baseDir(fileBaseDir);
+    }
 
     return opts.build();
   }
diff --git a/src/main/java/org/asciidoc/intellij/asciidoc/PrependConfig.java b/src/main/java/org/asciidoc/intellij/asciidoc/PrependConfig.java
index 20ef5e412..4f67d6434 100644
--- a/src/main/java/org/asciidoc/intellij/asciidoc/PrependConfig.java
+++ b/src/main/java/org/asciidoc/intellij/asciidoc/PrependConfig.java
@@ -3,6 +3,7 @@
 import org.asciidoctor.ast.Document;
 import org.asciidoctor.extension.Preprocessor;
 import org.asciidoctor.extension.PreprocessorReader;
+import org.asciidoctor.extension.Reader;
 
 import java.util.Collections;
 
@@ -17,11 +18,12 @@ public class PrependConfig extends Preprocessor {
   private String config = "";
 
   @Override
-  public void process(Document document, PreprocessorReader reader) {
-    if (config.length() != 0) {
-      // otherwise an empty line at the beginning breaks level 0 detection
-      reader.push_include(config, null, null, 1, Collections.emptyMap());
+  public Reader process(Document document, PreprocessorReader reader) {
+    if (!config.isEmpty()) {
+      // otherwise, an empty line at the beginning breaks level 0 detection
+      reader.pushInclude(config, null, null, 1, Collections.emptyMap());
     }
+    return null;
   }
 
   public void setConfig(String config) {
diff --git a/src/main/java/org/asciidoc/intellij/editor/browser/BrowserPanel.java b/src/main/java/org/asciidoc/intellij/editor/browser/BrowserPanel.java
index 729052d21..5922506fe 100644
--- a/src/main/java/org/asciidoc/intellij/editor/browser/BrowserPanel.java
+++ b/src/main/java/org/asciidoc/intellij/editor/browser/BrowserPanel.java
@@ -97,8 +97,6 @@ public class BrowserPanel implements Disposable {
   @Nullable
   private String myGoogleFontsCssLink;
   @Nullable
-  private String myDroidSansMonoCssLink;
-  @Nullable
   private String myMermaidScript;
   @Nullable
   private String myAsciidoctorTabsScript;
@@ -145,7 +143,6 @@ public BrowserPanel() {
       myFontAwesomeCssLink = "<link rel=\"stylesheet\" data-default href=\"" + PreviewStaticServer.getStyleUrl("font-awesome/css/font-awesome.min.css") + "\">";
       myDejavuCssLink = "<link rel=\"stylesheet\" data-default href=\"" + PreviewStaticServer.getStyleUrl("dejavu/dejavu.css") + "\">";
       myGoogleFontsCssLink = "<link rel=\"stylesheet\" data-default href=\"" + PreviewStaticServer.getStyleUrl("googlefonts/googlefonts.css") + "\">";
-      myDroidSansMonoCssLink = "<link rel=\"stylesheet\" data-default href=\"" + PreviewStaticServer.getStyleUrl("googlefonts/droidsansmono.css") + "\">";
       myMermaidScript = "<script src=\"" + PreviewStaticServer.getScriptUrl("mermaid/mermaid.min.js") + "\"></script>" +
         "<script>mermaid.initialize(); window.mermaid = mermaid; </script>";
       myAsciidoctorTabsScript = "<script src=\"" + PreviewStaticServer.getScriptUrl("tabs.js") + "\"></script>";